Process Robustness against Photoresist Outgassing in Single-Wafer High-Energy Implanters

Sumitomo Heavy Industries Ion Technology's (SMIT) single-wafer ultra-high energy implanter, the S-UHE, is designed for fabrication of cutting edge image sensors. A unique symmetric and energy contamination free beam line design is introduced to meet very tight requirements for dose uniformity and depth profile reproducibility even in applications with severe photoresist (PR) outgassing. Angle integrity in the horizontal direction is realized by a symmetric electrostatic beam scanner and electrostatic parallelizing lens. Exceptionally low energy contamination and angle integrity in the vertical direction is secured by an angular energy filter. This paper describes the superior dopant uniformity performance and reproducible dopant depth profile in spite of severe PR outgassing.